Tone tubes with acoustic actions for sound-recording and soundreproducing apparatus



y 1932 A. J J. VAN AKKEREN 39 TONE TUBES WITH ACOUSTIC ACTIONS FOR SOUND RECORDING AND SOUND REPRODUCING APPARATUS Filed lay 13, 1927 N ama Patented July 5, 1932 UNITED STATES [PATENT orrlca ANTONIUS J'OEANNES JACOBUS YA! AKKEBEN, F 'I-HE HAGUE, NETHERLANDS TONE TUBES WITH ACOUSTIC ACTIONS FOB SOUND-RECORDING AND SOUND- v BEPBODUOING APPARATUS Application filed 1m; 18, 182?,Ber1al No. 191,187, and in the Netherlands July 15, 1936. I

This invention relates to a tone tube for sound-recording or sound-reproducing apparatus, more articularly for the re roduction of music, w ereby an acoustic e act is pro- 5 duced. It consists in the fact that the tone tube comprises two or more tubes of different len hs, preferably with a difference in length of rom to metres, between which the sound waves are distributed, owing to the 10 fact that they divide into two or more parts, either at the point where the sound waves are produced, or after these waves have already traversed a certain length in an undivided condition. 15 In order to obtain an acoustic efi'ect in talking machines by the formation of echoes, it has already been proposedto attach to each side of a sound box containing a diaphragm in the centre a rotatable tone arm, which ex- 2 tends into a stationary horn.

One tone arm is in this case short and the other not morethan 5 metres longer, so that the sound waves must traverse paths ofdifferent lengths before they leave the horn. A

difference in length of 5 metres, however, is not sufiicient to produce a real acoustic effect. This construction moreover is practically unusable, since the two tone arms, although rotatable about the same axis, cannot execute so the necessar vertical movements which the inevitable s ight oscillation of the record renders necessar If the invention is applied to a talking machine it renders possible not only the hOIl- 85 zontal and vertical movements of the needle, but also the utilization of more than two air paths of different lengths, and the differences in length can be made so great that a normal acoustic effect is obtained. The longer-tube may for example be coiled helically and lodged in the talking machine case.

. Furthermore according to the invention the strength of the echo, as compared with 5 the strength of the original note can be very simply regulated by providing a pivoted flap at the point where the tone tube divides, this flap determining by its position the ratio in which the sound waves are divided. The

difierent air paths may open jointly or sepacasioning difi'erent acoustic 'efiects.

box 2. Both are of the usual construction. The other end of the tone arm opens into a stationary tube 3, which branches into two tubes 4 and 5. The tube 4 extends directly into a horn 6, while the long tube 5 is coiled helically and then ultimately opens into a 05 horn 7 At the point where the tube 3 divides, there is a pivoted flap or valve 8, which can be adjusted from the outside by means of a knob Be.

It is clear that with this construction the sound waves passing out of the tone arm can be divided in any desired ratio into an origi nal note and an echo. Furthermore it is immediately obvious that the tube 5 can be again branched one or more times into tubes vIt 0 different lengths, thereby producing two or more echoes in rapid succession, thus oc- There is the unexpected result that from a talking machine with a tone tube according to the invention, a more powerful note seems to come than from an ordinarytalking machine.

When the invention is applied to apparatus for the recording of music, records are obtained in which the echo efiect is already present, so that these will produce an acoustic effect in reproducing apparatus of ordinary construction, that is to say, with a sin-- gle tone tube.

What I claim is:

1. A device for use in connection with. sound-recording and sound-reproducing apparatus comprising, in combination with. a sound box, a single tone arm carrying the sound box, a fixed tube into which the tons arm opens, and two tubes of difierent length branched from the fixed tube, the difference of length of the tube branches being from 10130-20 meters.

2. A device for use in connection .with

' sound record recording and sound reproducing apparatus comprising in combination with a sound box, a sin 1e tone arm carrying the sound box, a fixed tu into which the tone 5 arm opens, a pair of juxtagosed horns, and two tubes branching from t e fixed tube one being short and directly connected to one horn while the other has a length of to 20 meters longer than the short tube and is 10 coiled helically and connected to the remaining horn.

3. A device as claimed in claim 2, in combination with means for controlling the ratio of the sound passing through the branch tubes including a pivoted alve member situated in the fixed tube at its point of mmture with the branch tubes.

In testimony whereof I afiix my signature.

ANTONIUS JOHANNES JACOBUS nn AKKEREI. 

